Studies have demonstrated that the external bacterial flora of the patients in most cases is the actual source of infection. The objective of antisepsis is to eliminate or significantly reduce the number of microorganisms in the surgical field at the time of surgery. The eyelids and the conjunctiva are considered to be quite common sources of bacteria that can lead to endophthalmitis. Thus, it is believed that by reducing the number and growth of bacteria on the ocular surface and adnexa before surgery, the risk of postoperative infection would be lower. Povidone-iodine 5% eye drops has been used in preoperative cataract surgery to prevent endophthalmitis and is the standard prophylactic action in preventing postoperative endophthalmitis being widely compared with other antibiotic eye drops and their associations. The standard procedure of prophylaxis of postoperative endophthalmitis corresponds to applying a single drop of povidone-iodine 2min before any intraocular surgical procedure. However, few studies have assessed the effectiveness of povidone-iodine 5% eye drops using different dosing regimens to achieve the best bactericidal effect. The aim of this study is to investigate different dosages with respect to the use of povidone-iodine drops to optimize the effectiveness of the agent, ensuring the best exogenous endophthalmitis prophylaxis.